All he did is "discover" a generator of the group of units of the integers modulo 9, namely, 2. Mod 9, the powers of 2 are 2, 4, 8, 7, 5, 1. The remaining three

All he did is "discover" a generator of the group of units of the integers modulo 9, namely, 2. Mod 9, the powers of 2 are 2, 4, 8, 7, 5, 1. The remaining three numbers modulo 9 he joins in a triangle. This is all.